Do not append to default values in {String,Int}Slice

I added the ability to do: `-s=bob -s=john` and get `[]string{"bob", "john"}`

But if a default value was set to say `[]string{"eric"}` the above
operation was mistakenly resulting in: `[]string{"eric", "bob", "john"}
which was obviously not what was intended.

This is fixed by tracking if a value was parsed and overwriting the
default on the first time -s is found, but we append the 2+ time.

1 files changed, 60 insertions, 0 deletions

diff --git a/string_slice_test.go b/string_slice_test.go
index 63eb9de..e8847d5 100644
--- a/string_slice_test.go
+++ b/string_slice_test.go
@@ -16,6 +16,12 @@ func setUpSSFlagSet(ssp *[]string) *FlagSet {
 	return f
 }
 
+func setUpSSFlagSetWithDefault(ssp *[]string) *FlagSet {
+	f := NewFlagSet("test", ContinueOnError)
+	f.StringSliceVar(ssp, "ss", []string{"default", "values"}, "Command seperated list!")
+	return f
+}
+
 func TestEmptySS(t *testing.T) {
 	var ss []string
 	f := setUpSSFlagSet(&ss)
@@ -60,6 +66,60 @@ func TestSS(t *testing.T) {
 	}
 }
 
+func TestSSDefault(t *testing.T) {
+	var ss []string
+	f := setUpSSFlagSetWithDefault(&ss)
+
+	vals := []string{"default", "values"}
+
+	err := f.Parse([]string{})
+	if err != nil {
+		t.Fatal("expected no error; got", err)
+	}
+	for i, v := range ss {
+		if vals[i] != v {
+			t.Fatalf("expected ss[%d] to be %s but got: %s", i, vals[i], v)
+		}
+	}
+
+	getSS, err := f.GetStringSlice("ss")
+	if err != nil {
+		t.Fatal("got an error from GetStringSlice():", err)
+	}
+	for i, v := range getSS {
+		if vals[i] != v {
+			t.Fatalf("expected ss[%d] to be %s from GetStringSlice but got: %s", i, vals[i], v)
+		}
+	}
+}
+
+func TestSSWithDefault(t *testing.T) {
+	var ss []string
+	f := setUpSSFlagSetWithDefault(&ss)
+
+	vals := []string{"one", "two", "4", "3"}
+	arg := fmt.Sprintf("--ss=%s", strings.Join(vals, ","))
+	err := f.Parse([]string{arg})
+	if err != nil {
+		t.Fatal("expected no error; got", err)
+	}
+	for i, v := range ss {
+		if vals[i] != v {
+			t.Fatalf("expected ss[%d] to be %s but got: %s", i, vals[i], v)
+		}
+	}
+
+	getSS, err := f.GetStringSlice("ss")
+	if err != nil {
+		t.Fatal("got an error from GetStringSlice():", err)
+	}
+	for i, v := range getSS {
+		if vals[i] != v {
+			t.Fatalf("expected ss[%d] to be %s from GetStringSlice but got: %s", i, vals[i], v)
+		}
+	}
+}
+
 func TestSSCalledTwice(t *testing.T) {
 	var ss []string
 	f := setUpSSFlagSet(&ss)